Dr Vetrovec intends to perform his version of the trick at atmospheric pressure, and using permanent magnets.

维特威克博士想要在大气压力下使用永来实这种把戏。

This makes electromagnets quite different from permanent magnets.

这使得电与永有很大同。

This is different from a permanent magnet because permanent magnets don't need this wire.

这与永同，因为永需要这种电线。

So let's take a look at that and compare permanent magnets to electromagnets.

让我们看一下并将永与电进行比较。

Permanent magnets also have fixed poles.

永也有固定极。

On the other hand, permanent magnets are always on.

另一方面，永始终处于开启状态。

Permanent magnets have a fixed strength, but we just talked about how we can change the strength of electromagnets, so electromagnets have adjustable strength.

永强度是固定，但是我们刚才讲了如何改变电铁强度，所以电铁强度是可调。

Permanent magnets do not need a power source, but this means that we can also turn electromagnets on and off, which is pretty cool when you think about it.

永需要电源，但这意味着我们也可以打开和关闭电，想想看，这真是太酷了。